A Dirty Sanchez is a Sexual act that is usually performed by White people typically Trailer trash. It is when a couple of the same or opposite sex engage in anal sex and the one who is giving it to the other in the ass will either take either his shit covered Dick or finger and make a shit mustache then calling it a dirty Sanchez because from a Caucasian point of view it might resemble a thin wispy Hispanic mustache.

Chad and Lance were butt fucking each other all night long. Chad enjoys the smell of shit so he asked Lance if he can please give him a Dirty Sanchez.

so your fucking a bitch in the ass. and sinse she did not show you the curtacy of whiping good enough, you give her back whats hers by whiping it on her uper lip, which gives her a dirty mexican mustache

me and your mom..your mom comes out with a mustache..heehee, oh yea thats a dirty sanchez

The etymological history of the term "Dirty Sanchez" originated with one Generalissimo Leopoldo Sanchez, who led the infamous and ill-fated raid on the Panoche Grande brothel in 1848. Mistakenly believing he was counter-attacking to fend off an American incursion, he resigned himself to a life of tequila and debauchery in the alleys of Juarez. He was known for sporting a excrement mustache and a large silver-toothed smile.